Users with brand-new Lumias, such as the Lumia 930 and 630 already have Windows Phone 8.1 and Cyan. But just about every existing Lumia handset will be getting the new operating system and firmware refresh, as will almost all other non-Lumia Windows Phone 8 handsets.

Currently all of the Lumia models on that page are listed as still "in testing."

Microsoft released to manufacturing the Windows Phone 8.1 back in late March/early April. Anyone signing up as a developer was able to get that RTM'd version of Windows Phone 8.1 as of early April. Since then, Microsoft has updated the operating system a few times.

Company officials repeatedly have told users to expect to get the Windows Phone 8.1 release beginning this summer. The exact rollout timing is determined by handset makers and carriers.

Those with Lumia Windows Phone devices -- the vast majority of the Windows Phone installed base -- will get a firmware update codenamed Cyan, in addition to the Windows Phone 8.1 OS itself. The Cyan update includes new Nokia functionality, including a new, simplified user interface and full-resolution zooming and reframing and other fairly minor features. Cyan is tailored specifically for each Lumia model, meaning not every handset will get every Cyan feature.